Radar level gauge systems are today in use in a variety of fields of application for accurate level determination, as well as for determination of other product parameters, such as temperature, flow etc. For determining the level of a product by means of a radar level gauge system, electromagnetic signals are transmitted and propagated, usually by means of an antenna, towards a surface of the product, where signals are reflected. The reflected signals are received by the radar level gauge system, and the distance between a reference position and the surface of the product is determined by comparing the transmitted signals with the reflected signals. Based on this distance, the filling level can be determined.
Especially in open or semi-open applications, such as open tanks, floating-roof tanks, reservoirs, or even rivers or lakes, the operation of a radar level gauge system is typically subject to government regulations in respect of such parameters as the frequency and power of the transmitted signals.
According to such existing and/or anticipated regulations, the transmission power should be limited to a certain level. According to other forms or aspects of such regulations, the average emitted power, over time or for a given number of sources of emission, may be limited to a certain level. In such average-power-based regulations, a higher peak power may be permitted so long as the spatial and/or temporal average is below the stipulated value.
At the same time, the quality-of-measurement, such as the accuracy with respect to distance, of the radar level gauge system should not be sacrificed to obtain this transmission power level.
Conventional radar level gauge systems are generally not well adapted to fulfilling transmission power related regulations while at the same time achieving a high quality-of-measurement level.